Sound-reproducer.



A. N. PIERMAN.

SOUND REPRODUOER.

APPLICATION FILED MAY 1, 1909.

13-10311 1 Patented Nov. 28, 1911.

UNITED STATES PATENT orrron.

ALEXANDER NJPIERMAN, OF NEWARK, NEW JERSEY, ASSIGNOR,

MENTS, TO THOMAS A. EDISON, INCORPORATED, OF WEST ORANGE, NEW. JERSEY, A

CORPORATION OI!" NEW JERSEY.

sounn-nnrnonncnn.

riatented Nov. .28, 1911.

Application filedMay 1, 1909. Serial No. 493,281.

-producers, of which the following is a description.

My invention relates to talkingmachines of the pneumatic type, or, generally speak ing,,of the type i'nwhich undulations corresponding to sound waves are impressed upon a .current of any suitable moving fluid by the operation of a suitable valve through which the fluid is allowed or caused to pass, the'va-lve being operated in accordance with the sound waves, as by connection with a reproducing stylus tracking a record groove.

The objects of my invention are to construct a sound reproducer in which the moving fluid is caused to operate a sensitive valve of a novel character in a novel manner, whereby a sound reproduction of clear and excellent qualities and the desired degree of loudness or amplification is secured.

The valve or vibratory member or members constructed in accordance with my invention is of minimum mass, whereby defects due to inertia and momentum of parts are largely avoided. In accordance withthese objects, thin, flexible, reed-like members are interposed in the path of the moving fluid current and are vibrated in accordance with sound vibrations to set up corresponding undulations in the moving fluid current in the sound box of the re producer. l

In the preferred form of my invention, a port plate is-provided having one or more slit-like ports therein, upon which ports are seated thin, flexible, reed-like members of elastic material which are placed under tension and secured to the port plate at both ends. Also, preferably, these reed-like members are burnished or otherwise given such a' conformation. that they rest upon the mouths of the ports in close contact, partly within the same, to accurately close the said ports when the members are in their normal position. The reed-like members are joined together and are flexed by connection with the stylus to vary the extent of opening of the ports to a greater or less extent in accordance with the sound vibravibrate in parts and specification and claims.

So far as I am aware, thevalves'or vibratory members pfdevices of the general type BY MESNE ASSIGN- referred to above will appear below in the referred to above constructed prior to my invention have. been generally in the form of rigid plates or bodies whlch are moved bodily in accordancewith sound vibrations to vary the extentof opening of the ports, as by moving thesame in planes perpendicular to theplane in. which the-mouths of the ports are situated, or parallel thereto, or by an angular movement, the valves being pivoted orrbalanced on a knife-edge, or the like, atone side of the orts. It has also been proposed to constitute the valve of elastic material and secure it firmly at one extremity, and vibrate the same across the port opening in the manner of a tunin fork,

the material of the valve flexing chic y in a line adjacent to its point of support, this manner of mounting being therefore similar to the pivotal mounting referred to above.

In the case of the rigid valves a considerable amount v of mass is necessitated, with consequent inertia and loss of sensitiveness, and

in the ease of the vibratory valves 'last re:

ferred to, it has been impossible to make the tongues thin and light, since in that case they might set up audible. vibrations of their own. The reed like members of my inven.- tidn, onfthecontrary, are held at both ends,

preferablyflnnder tension, and hence vibrate not like tuning forks but rather in the manner of violin strings. The analogy, however, is not complete. The reed-like members are constrained to vibrate only in accordance with the sound vibrations, to be reproduced, and can not reduce audible tones of their own. Also, t ey are-of such proportions and so short that they cannot produce nodes to produce audible tones. The stiffening of the material by the burnishing referred to above also conduces to this result.

Reference is hereby made to the accompanying drawings, specification, in which the same reference forming part of this numerals aregilsed throughout to denote cor-' responding parts and in which- Figure 1 is a side elevation, partly in section, of a sound reprodiicer embodying my invention. Fig. 2 is a plan view of the port plate with the valve members secured thereto.' Fig. 3 is an enlarged fragmentary cross section through one of the ports oj'ythe port plate showing one of the reed-lik' members burnished into contact therewith, and Fig.

" 4 is a detail view showing the preferred method'bf securing the reed-like members to the port plate under tension.

Referring to the drawings, the sound box 1 ma be formed with two chambers 2 and in position against the shoulder ofthe circular wall of the chamber 3 by means of the ring 9 which is screwed into the depending flange 10 of the sound box to hold the closure 8.tightly in position. The floating weight 11 is pivotally mounted at 12 to the block 13 which is mounted as by the screw 14: on the lower surface of the depending flange 10. The stylus lever-15 is pivotally mounted at 16 to the lugs 17 depending from the floating weight, and the said stylus lever is provided with stylus 18. All of the above mentioned parts are common.

The ports 1, which are preferably in the form of lengthened slits, are normally closed by means of the flexible reed like members 19 seated upon the same. These members are very thin and preferably are .formed of a light metal such as aluminium.

These reeds are secured in position on the port plate by fastening them's'ecurely to the same at both their ends at the opposite extremities pf the ports. I prefer to secure the reed's -fi) in position by the means shown in the drawings. As there illustrated, the strips 20 and 21 are placed transversely across the ends of reeds l9 beyond the two extremities of the ports 4, and screws 22 are screwed through the stri s 20 and 21 and, into the port plate 5, t e shanks of the screws extending between the reed-like members 19 and the heads of the screws each overlapping one of the said reeds 19 on each side of theqsamea By this means a very secure connection is made'which is at the same time detachable. Itlis, of course, obvious that members 19 might be secured permanently to the plate 5 as by solder. The reeds 19 are tastened together as by strip 23, which is soldered or otherwise secured to -the same transversely-of the same and midway between the strips 20 and 21. The link 24 which is attached to the tail. of stylus lever 15 is also secured to strip 23. I prefer to use the construction shown in the drawings, in which link 24 passes through a hole in strip 23 and is provided points, the pressure of air or other fluid passing from chamber 3 through ports 1 into chamber 2 tending to constantly keep the reeds 19- flexed upwardly. The result of this construction is that when the stylus 18 passes into depressions in the record groove, the currentof air or other fluid passing through the port plates flexes the reeds 19'to open the ports to a greater extent, whilewhen the stylus 18 passes over bills or, shallower places in the record groove',' the link 24 draws the 'reeds.1'9 down to reduce the extent of opening of the ports. It is, of course, obvious thatthe proportion of parts as shown could be changed without departingfrom the spirit of the invention, and that, if desired, the direction of flow of the fiuid,could be reversed and the valve seated on the opposite side of the port plate 5 from that indicated with appropriate connection to the stylus lever.

Preferably, the reeds 19 are secured in position and held under a uniform tension; This may be secured in a number of ways,

as, for example, that indicated in Fig. 4. v

Here, the port plate 5 is represented as being formed with slightly raised bearing surfaces surrounding the orifices of the ports on the side of the plate on which'the reeds are mounted, the lips so formed having their edges rounded with a' smootheurve beyond tlie'ends of the slit-like ports, as shown at 26. The reeds 19 are placed in position over the ports 4 and are so held temporarily by any suitable means. The screws 22 are then secured in position in the portions of the .pert plate ofreduced thickness, as indicated, and by the pressure produced.- by their heads upon that portion of the reeds 1'9 Iyingon curvedportions; 25 ofthe port plate" 5, a tension'is produced which is the same in all the reeds 19,-since the adjust-1,.

ment of screws 22 is the same in each case.

When'the reeds 19 have been properly secured in position, they are preferably forced into close contact-with their bearing surfaces,-and bent somewhat into the mouths of the ports, in any suitable manner, as with a burnls'hing tool, as-indicated at 27in Fig.

3, to cause the said reeds 19 to conformv closely to the irregularities of the mouths of the ports, and thus normally seat themselves accurately and closely thereon. The valve, so' produced operates entirely by elastic fiexure, vibrating back and forth in "symmetricalarcs to a very slight extent to increase or decrease the amount of port open ing and admitting the current of air into the chamber 2 in a series of pufis. It would seem that the reeds 19 normally entirely close the. ports 4. The valveso constructed is exceedingly sensitive and copies the vibrations of the stylus with amplification and with great faithfulness. Any desired numberet ports and correspondingreeds may be i sed, tlie'loudness of the sound reproduced" "varying. with the number used.

here, in the various claims, I ha-.v,e-r-

ferred' to members seated upon the ports, it

istobe'rmderstood that the 'reed-like members maybe seated upon either the upper or the lower surface of theport plate as-previously-stated, and by the language used I ent is as follows:

do not limit myself to the seating of themembers upon the upper surface of the plate merely. v l

Having now described my invention, what I claim and desire to protect by Letters Patrigidly at both extremities, seated upon and covering said ports, and means fol-flexing the said members in accordance with sound vibrations, substantially as described.

2. In a sound reproducer, the combination of a hollow body containing chambers communicating through a port, a stretched member of elastic material held rigidly at both extremities, seated upon and covering said port, and means for flexing the said member in accordance with sound vibrations, substantially as described.

3. In a'sound reproducer, the combination of a hollow body containing chambers communicating through one or more ports, thin members of elastic material seated one upon each of said ports, means situated at both extremities of said members for holding the same immovable at'both ends, and means for flexing the said members in accordance with sound vibrations, substantially as described.

4. In a sound reproducer, the combination with a sound box and means for conveyinga fluid therethrough, of elongated flexible means interposed in the path of said fluid for producing undulations therein by its flexure, and means for flexing the said means in arcs having their centers in a single straight line in accordance with soundvibrations, substantially as .described.

5. In a sound reproducer, the combination with a sound box and means for conveying a' fluid therethrough, of a vibrating thin strip interposed in the path of said fluid and held only at both ends for producing undulations 111 said fluid, andmeans for causing said strip to vibrate substantially as-a;,.whole in accordance with sound vibra tion's, substantially as described.

6. In a soundv reproducer, the combination with a sound box and means for conveying a fluid therethrough, of a vibrating thin strip interposed in the path of said fluid and held only at both ends for producing undulations insaid fluid, and means acting-upon saidstrip substantially midwaybetween itsends 'fiiifcausing the same to vibrate in accordance with sound vibrations, substantially as described.

,7'. In a sound reproducer, the combination with a sound box and means for conveying .a fluid therethrough, of a ,member inter posed in the path of said fluid and provided with a passageway through'which the fluid passes, and a vibratory reed covering said passageway and held firmly at both ends, and. means forflexing the said reed touncover the said passageway more or less in accordance with sound vibrations, substan-" tially as described.

8. In a-sound reproducer, the combination with asound box and means for conveying a fluidtherethrough, of a .member interposed in the path of said fluid and provided with a passageway through which the fluid *passes, a vibratory reed held under tension and secured at both ends to cover said passageway, and means for flexing the said reed to uncover the said passageway more or less in accordance with sound vibrations, sub-,

stantially as described.

9. In a sound reproducer, the combination of a hollow body containing chambers com municating through a plurality of slit-like ports, vibratory reed-like members of somewhat elastic material seated one upon each of said ports and covering the same, means for securing fixedly both the ends of all said members, and means for flexing all said members together to open said ports more or less in accordance with sound vibrations, substantially as described.

10. In a sound reproducer, the combination of a hollow body containing chambers communicating through a plurality .of slitlike ports, vibratory reed-like members of somewhat elastic material seated one upon each of saidports and covering the same, means for holding all said members under an equal tension and anchoring the ends thereof, and means for flexing all said memerstogether to open said ports more or less in accordance with sound vibrations, substantially as described.

11. In a sound reproducer, thecombination of a hollow body containing chambers communicating through one or more ports, a valve of elastic material rigidly held at both ends and seated upon said ports, and

means for flexing the said valve for varynormally seated upon said ports and convexed somewhat to fit accurately into the adjacent orifices of the same, means rigidly holding the ends of said members and means for flexing the said members for varying the extent of openin of said ports in accordance with soun vibrations, substantially as described.

13. In a sound reproducer,-the combination of a hollow body containing chambers communicating through one or more ports, thin reed-like members of elastic material normally seated upon said ports and constituting a valve, means holding said mem- .bers rigidly at both ends, a stylus, and connections from the said stylus to the said or ports in the same on the opposite side thereof, a stylus and a oneway connection from said stylus to said member or members for flexing the same toward the said plate in accordance with movements of said stylusin one direction, substantially as described.

, 15. In a sound reproducer, the combination with a sound box, of a ported plate therein, means for introducing fluid into.

said sound box on the lower side of said plate, a member or members. of elastic material secured upon saidplate at both-em.

tremities and covering the said port or ports in the same 'on the upper side thereof, a stylus below the plate and a one-wa 4;;0..I1- nection from said stylus to said mefn 31:1 or

members for flexing-the same toward the" said plate in accordance with movements of said stylus in one direction, substantially as described.- Y I 16. As a new article of manufacture, a

port plate for an air sound reproducer, having slit-like ports therein, and thin flexible reed-like members seated upon said ports and bent or forced into'position to normally a closely cover thesame, substantially asdescribed. v 17. As a new article of manufacture, a

1 port plate for an air sound reproducer,'having slit-like ports therein, thin flexible reed- I :like members seated upon said ports and normally closely covermgthe same, and se- 'cured to the port plate at both ends, sub

stantially as described.

This specification signed and witnessed this 30th day of April 1909. ALEXANDER N.- PIERMAN. Witnesses! I DYER SMITH,

JOHN M. CANEIELD.

Copies of this patent may be 'obtained'for five cents each, by addressing the Commissioner otlatents, I

Washington, D. G. 

